During hospitalization, neonates are exposed to a stressful environment and a high number of painful procedures. If pain is not treated adequately, short- and long-term complications may develop. Despite evidence about neonatal pain and available guidelines, procedural pain remains undertreated. This gap between research and practice is mostly due to limited implementation of evidence-based knowledge and time constraints. This study describes in detail the development process of a complex interprofessional intervention to improve the management of procedural pain in neonates called NEODOL© (NEOnato DOLore). The framework of the Medical Research Council (MRC) for the development and evaluation of complex interventions was used as a methodological guide for the design of the NEODOL© intervention. The development of the intervention is based on several steps and multiple methods. To report this process, we used the Criteria for Reporting the Development of Complex Interventions in Healthcare (CReDECI 2). Additionally, we evaluated the content of the intervention using a Delphi method to obtain consensus from experts, stakeholders, and parents. The complex interprofessional intervention, NEODOL©, is developed and designed for three groups: healthcare professionals, parents, and neonates for a level IIb neonatal unit at a regional hospital in southern Switzerland. A total of 16 panelists participated in the Delphi process. At the end of the Delphi process, the panelists endorsed the NEODOL© intervention as important and feasible. Following the MRC guidelines, a multimethod process was used to develop a complex interprofessional intervention to improve the management of painful procedures in newborns. Complex interprofessional interventions need theoretical bases, careful development, and integration of stakeholders to provide a comprehensive approach. The NEODOL intervention consists of promising components and has the potential to improve the management of painful procedures and should facilitate the knowledge translation into practice.